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Why We Think There's a Multiverse, Not Just Our Universe
An anonymous reader writes "It's generally accepted that the Universe's history is best described by the Big Bang model, with General Relativity and Quantum Field Theory as the physical laws governing the underlying framework. It's also accepted that the Universe probably started off with an early period of cosmic inflation prior to that. Well, if you accept those things — as in, the standard picture of the Universe — then a multiverse is an inevitable consequence of the physics of the early Universe, and this article explains why that's the case."
That there is a universe out there where Sarah Palin is President.
But the turtles appear out of nowhere and are very far apart.
Why do cosmological theories of any merit always sound like they were written by Douglas Adams?
Please do not read this sig. Thank you.
Note that this isn't talking about the quantum mechanical multiverse where whenever a decoherence occurs you get branching of different copies. This is talking about a more concrete notion of multiverse where the early inflation spreads out so much that there are lots of little regions of observable space time which cannot observe each other.
or something less stupid, instead?
It doesn't make any sense to say that it's one big thing, but not one big thing at the same time.
Kind of like saying it's not one big cake sliced into wedges, it's lots of little cakes that have nothing to do with each other.
AND YET THEY OCCUPY THE SAME PLATTER.
I think that this is a great article, but...
It is obvious that there are parts of the universe that are not (and never have been) causally connected with our universe.Those are just the parts of our universe we can't see, which are inevitable in an infinite universe with a finite duration and a finite speed of light. You don't need either quantum mechanics or inflation for that, and it has never been called the "multiverse."
The multiverse in my experience means exclusively the idea that there are other parts of the universe with different physical laws. That idea is connected to the anthropic principle, and (IMHO) evading tough issues about the nature of physical laws. (Find the cosmological constant to be inconveniently small? That's OK! In a multiverse there are a gazillion universe with large cosmological constants and no life like ours, ours with a small one and our kind of life, and nothing left to explain!) "We" might think that there is that kind of multiverse, but "we" in this case decidedly does not include "me." (People like me tend to call such ideas "Just so stories," which in physics is an insult.)
I know it's karma suicide to post on something like this saying "I don't get it", but, well, I don't get it.
I've been reading about inflation, multiverses, and whatnot for a very long time at this point, and I like to think that I can give a reasonable explanation comprehensible to nontechnical people. I've come across some articles that were a lot of work to get through, and I've given up on some because I don't have the necessary math.
But this article was terrible. Its grammar is good and not overly complex; it doesn't use a lot of obscure words. It's written like a nice popularization piece, with important parts called out in bold and lots of illustrations. But the illustrations are baffling -- what's that "getting closer to a sphere" four-panel diagram credited to Ned Wright, and where does the text refer to it? What the heck is going on with those diagrams from Narlikar and Padmanabhan? What's with the black space-balls rolling around on the mini-golf course at the end?
I'd wonder if this is a Sokol-type troll, but I don't see anything obviously wrong in it -- there's just a bunch of stuff there that looks like explanations, but apparently isn't. Or maybe I'm just having a bad night.
I mean, I can handle the concept... so long as there's just ONE multiverse.
I think the next greatest feat in physics will not be a new discovery, but just figuring out how to explain the current state of knowledge to a high school student. How can the field progress if only a handful of people actually understand the information we now possess?
I'm not sure I understand what you mean. Are you saying we should only pursue theories and bodies of knowledge if the average idiot can understand them? I'm sure you'll agree that if it makes sense for physics, it makes sense for all areas, including... engineering.
So say goodbye to television, GPS (oops, there's some relativity physics in that too), computers of all sorts, and possibly even non-electronic internal combustion engines.
I'm willing to continue relying on people who deal in knowledge I don't understand, as long as I'm satisfied they're constrained by peers who are incented to find flaws in their arguments to keep them honest.
Hell, most people don't understand what *I* do for a living, and I'm just a senior manager in healthcare information systems.
I thought there were already concise terms for it. The universe IS the multiverse / partitioned universe. The part that we are in is called observable universe.
Better known as 318230.
It's generally accepted that the Universe's history is best described by the Big Bang model, with General Relativity and Quantum Field Theory as the physical laws governing the underlying framework.
No no no. It's generally accepted that each one of these theories taken individually is the best currently known description within its particular domain. It is not generally accepted that you can just throw them together and get an accurate description of the fundamental nature of the universe! In fact, we know you can't do that because general relativity and quantum field theory are deeply incompatible with each other. People have been working for half a century to find a single consistent theory that can reproduce the predictions of both. They've made a lot of progress, but we're still a long way from having any confidence about what the true fundamental theory is.
The picture of eternal inflation described in this article is plausible based on what we know. But it's still very speculative. That's true of any discussion of cosmology. Our current knowledge is just way too limited to have any confidence about it.
"I'm too busy to research this and form an educated opinion, but I do have time to tell everyone my uninformed opinion."
"God"=="supernatural"=="not allowed by physical (natural) law." All of the multiverses are supposedly governed by physical law.
Nothing in natural law (i.e. physics) forbids the existence of something that does not follow natural law. It does forbid something natural (or possessing natural qualities) from not following natural law (insofar as it possesses such quantities), but that does not mean something supernatural cannot exist.
"None can love freedom heartily, but good men; the rest love not freedom, but license." --John Milton
Really things were set up rather well initially. But it broke down almost immediately.
The big problem was that we let the government reinterpret their own rights.
So the executive gets executive privilege which lets them basically lie/keep secrets from the legislature/judiciary and through interpretation the judiciary gets legislative powers by getting the power to change the meaning of laws.
There are other examples but they're all perversions.
The Executive has no right to keep secrets of any kind from the legislature or the judiciary... these are interpreted powers.
The Judiciary assumed the right to interpret laws because how could they rule on the constitutionality of a law if they couldn't strike one down. The issue becomes especially thorny when they start reinterpreting the constitution itself which is the highest law in the land.
In regards to how these two compromises should have broken down:
1. Give the Judiciary and legislative branch a joint investigative power over the Executive that reports to either the full house or the select committees as desired by the Legislative. The Judiciary likewise can receive the reports however they like. But a major flaw in the system is that the executive is the only branch allowed to directly investigate anything. Which means when it needs to be investigated there is a conflict of interest. Hold executive funds in bank accounts controlled by the legislative so that their checks literally bounce the instant the legislative branch desires it. And the Judiciary can pull legal authority from the executive if it fails to comply... so a government order to X by the executive would suddenly lack all legal authority if the executive stopped complying with the Judiciary.
2. In regards to Courts assuming legislative powers the courts have a point that they need the power to modify laws however those powers have been pushed far too much. All they really need is to say "rewrite this bill because it conflicts with X". Or in the case that there is a Constitutional law that needs clarification, simply cite precedence on the law and if required request a law from the legislature that addresses the case specifically. In that way, the courts wouldn't be legislating but rather pointing out a problem to the legislature and requesting their clarification on the issue.
In any case, your idea reminds me of Frank Herbert book. I think it was "the Whipping Star"... In this future society there is an American type governmental system with the three conventional branches but there is also a fourth branch called "bureau of sabotage" which has the sole function of screwing up government. Mostly slowing it down, frustrating it, cocking it up, leaking information... generally making things not work very well. The theory being that government becomes a problem when it becomes efficient and a confused and hamstrung government is less ambitious and more solicitous of its citizens. The government is always kept on the brink of collapse so if the government ever loses the consent of the governed it will fold instantly.
Its an insane idea but its also an amusing one in these times of rampant government arrogance.
I've decided to stop wasting my time responding to AC trolls/sockpuppets... so if you want a response from me... login.
The ancient Greeks had this system - it's called Sortition, or drawing of lots - http://en.wikipedia.org/wiki/Sortition
The idea was that they didn't even vote, they just picked citizens at random for various committees, similar to how a jury is chosen.
If the "tired light hypothesis" was true, and the "observable" universe was actually much older than 14 billion years, if could be possible for a system at the edge of what we observe to take information it has observed from further way and repeat it in our direction. Thus, even if photons from further way could not make it to us, in theory information could -- potentially from a distributed internet spanning endless quadrillions of light years of space and time. Thus the idea of a cosmological horizon is incomplete:
http://en.wikipedia.org/wiki/Cosmological_horizon
By the way, Hugh Everett's life is another example of how poorly academia often rewards thinking outside the box: http://en.wikipedia.org/wiki/Hugh_Everett
Too bad he did not know how to escape "The Pleasure Trap" (which can be hard under stress):
http://www.drfuhrman.com/library/article16.aspx
Sci-fi author James P. Hogan used the Many Worlds Interpretation is some of his sci-fi novels from around the 1980s and 1990s (not sure exactly when the first was). Hogan often championed the academic underdog, arguing they should get a fairer hearing, whether they were right or not..
http://en.wikipedia.org/wiki/Tired_light
http://en.wikipedia.org/wiki/Electric_Universe_(physics)
http://en.wikipedia.org/wiki/Halton_Arp
http://www.thesunisiron.com/
Semmelweis is another example:
http://en.wikipedia.org/wiki/Semmelweis
One can see more extreme examples in times now despised enough to admit of them like Deutsche Physik or Lysenkoism:
http://en.wikipedia.org/wiki/Deutsche_Physik
http://en.wikipedia.org/wiki/Lysenkoism
Something to think about for the modern day (a book recommend by JP Hogan):
http://www.disciplined-minds.com/
"Who are you going to be? That is the question.
In this riveting book about the world of professional work, Jeff Schmidt demonstrates that the workplace is a battleground for the very identity of the individual, as is graduate school, where professionals are trained. He shows that professional work is inherently political, and that professionals are hired to subordinate their own vision and maintain strict "ideological discipline."
The hidden root of much career dissatisfaction, argues Schmidt, is the professional's lack of control over the political component of his or her creative work. Many professionals set out to make a contribution to society and add meaning to their lives. Yet our system of professional education and employment abusively inculcates an acceptance of politically subordinate roles in which professionals typically do not make a significant difference, undermining the creative potential of individuals, organizations and even democracy.
Schmidt details the battle one must fight to be an independent thinker and to pursue one's own social vision in today's corporate society. He shows how an honest reassessment of what it really means to be a professional employee can be remarkably liberating. After reading this brutally frank book, no one who works for a living will ever think the same way about his or her job."
A different-but-related take on that by Freeman Dyson:
http://edge.org/conversation/heretical-thoughts-about-science-and-society
A 21st century issue: the irony of technologies of abundance in the hands of those still thinking in terms of scarcity.
Scientists are not so naive as to simply think "it is expanding now, therefore it has always been expanding." The main reasons why we think there was a big bang are (http://en.wikipedia.org/wiki/Big_Bang#Observational_evidence):
1) The universe is not just expanding, it's expanding in such a way that the relationship between distance and speed matches up neatly along smooth curves.
2) We can see (in microwave telescopes) the cosmic background radiation just where it should be, at just the frequency that was predicted if there had been a big bang (note the prediction was made in 1948, but the microwaves were not measured until 1965).
3) We can see gas clouds in the far distance (12 billion light years), which we see as they appeared 12 billion years ago, which are made of hydrogen and helium in the proportions that we expect would have been made in the big bang, and without the heavier elements that we think would not have been made in a big bang, and there is no other theory that has been able to explain the proportions of the light elements.
4) The way galaxies and quasars are distributed and the way they appear to have developed over time matches what we think would have happened if there had been a big bang (and rules out other ideas such as a steady-state universe).
You also asked:
You suggest we should be believers in this everything from nothing theory without the least bit of skepticism?
No scientist would suggest that you believe any theory without skepticism. Certainly, be skeptical! But skepticism is not the same as refusing to accept an idea just because it sounds far-fetched. If someone does come up with a better theory (where "better" = "makes predictions that match what we actually observe more closely and more efficiently than other theories"), then by all means, out with the old theory and in with the new. And it's certainly fine to attempt to poke holes in the current theory -- indeed, there is surely a Nobel Prize waiting for the person who proves that there was no big bang! But poking holes in the theory has to be done by either finding out that the theory contains contradictions, or finding that it fails to explain something that we can see happens in reality. One doesn't get the Nobel Prize for saying "that doesn't sound right."